1. Field of the Invention
The present invention relates to a lighting fixture including a light-emitting section composed of a plurality of semiconductor light-emitting devices arranged on a substrate.
2. Description of Related Art
In a lighting fixture including a light-emitting section composed of a plurality of semiconductor light-emitting devices arranged on a substrate, a radiator configured to radiate heat generated by the semiconductor light-emitting devices is provided. Examples of a lighting fixture which uses LEDs as semiconductor light-emitting devices and is designed with heat radiation in mind include an LED lighting fixture which has good heat radiating effect to offer an extended useful life. Such an LED lighting fixture is disclosed in, for example, Japanese Utility Model No. 3,146,172 (hereinafter referred to as Document 1).
The LED lighting fixture described in Document 1 is composed of an aluminum extruded radiator base, an LED module, a condensing plate, a translucent cover, and electric plugs provided at two ends. The LED module is composed of a substrate which is fixed to the radiation base and a plurality of LED lights electrically connected to the substrate. The condensing plate is fixed on a bottom plate of the radiator base, and the condensing plate and the translucent cover fixedly fit into locking grooves, respectively, formed in the radiator base. The electric plugs are connected to the two ends, respectively, of the radiator base, and the substrate is electrically connected to the electric plugs. The LED lighting fixture is configured such that heat generated by the LED module is conducted to the radiator base of an aluminum extruded material and is rapidly radiated.
In Document 1, a main body of the lighting fixture is made of the aluminum extruded material, and the main body as a housing serving both as a radiator and a fixture main body has improved heat radiating effect. However, further improvement in heat radiating effect requires an increase in radiator size. Additionally, heightwise lengths of radiator fins of the radiator base of the aluminum extruded material are equal. Accordingly, if the radiator fins are directly attached to a ceiling surface, an airflow direction is limited, which may lead to restrictions on the heat radiating effect.